<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org">
<body>
<h1>content</h1>
<form method="post" action="/logout">
    <button type="submit">退出</button>
</form>
<p>我是登录后才可以看的页面</p>
</body>
</html>